1. Field of the Invention
This invention relates to the manufacture of optical assemblies. More particularly this invention relates to the manufacture of a precisely aligned array of optical fibers.
2. Description of the Related Art
In the past, the assembly and manufacture of optical fiber arrays has been largely time consuming and prone to quality control problems. The latest developments in optical cross-connect assemblies have only magnified these problems. A general demand for more precisely constructed assemblies having greater reliability has translated into a demand for better manufacturing apparatus and processes. For example, the newest cross-connect assemblies place extreme importance on a well-adjusted optical system. These devices rely on the reception of modulated light on a light-receiving device from a multiplicity of fibers, in which the parameters of operation are precisely known differences in phase shift and polarization of the individual light beams. If the optical system is not finely tuned, then the device will not operate optimally, or may fail entirely. Precisely manufactured arrays of optical fibers are components of such cross-connect assemblies.
One way of ensuring an optical fiber array of high quality is to increase labor intensity and quality control. The increased labor allows more time per optical fiber array for alignment and adjustment. Increased quality control results in rejection of substandard optical fiber arrays. The disadvantages of this approach are dramatically increased cost, and the discarding of parts and material upon recognition of failure. A better strategy is to manufacture storage devices with maximized quality and efficiency.
As mentioned previously, parts and labor are the most expensive elements of an optical fiber array. In the past, optical elements were positioned by hand. An assembler would hold the elements in place and apply glue. Quality control would later determine if the optical part were properly placed. The problem with this method is that in the case of a misplaced piece additional labor is uselessly added to an optical fiber array. Typically, any repair attempt destroys the glued part, and increases labor cost.
In the present invention, optics are inspected during the assembly or immediately following assembly. An improved manufacturing technique for optical fiber arrays employs optical feedback in a partially assembled cross-connect assembly using an inspection camera. This allows immediate reworking of a problematic part. In the present invention, a video microscope is used to check the alignment of the optical fiber array during the manufacturing process. After the optical fiber array has been glued or otherwise affixed, then an optical device may be used to measure the performance of the glued assembly.
It is a primary object of some aspects of the present invention to align optical fiber array assemblies during manufacture in a precise and efficient manner.
It is another object of some aspects of the present invention to reduce the cost of manufacturing optical devices that employ optical fiber array assemblies.
The invention provides an apparatus for manufacturing a fiberoptic device, comprising a first stage, and a fiber rotator disposed on the first stage. The fiber rotator carries an optical fiber therein, and the stage is arranged to rotate the optical fiber about its optical axis. The apparatus further includes a second stage for holding a silicon slab, a fiber gripping assembly that is disposed between the first stage and the second stage for gripping an intermediate portion of the optical fiber. The apparatus further includes a first viewer directed toward the silicon slab along a Y-axis, and a second viewer directed toward an end face of the optical fiber in a Z-axis. Responsive to views provided by the first viewer and the second viewer, the first stage, the second stage, the fiber rotator, and the fiber gripping assembly are manipulated to establish the optical fiber in a desired position on the silicon slab.
According to another aspect of the invention, the apparatus includes a third stage, and a weight mounted on the third stage. A free end of the weight impinges on the optical fiber to urge an end portion of the optical fiber onto the silicon slab.
According to another aspect of the invention, the third stage is movable on the X-axis and the Z-axis.
According to still another aspect of the invention, the weight is pivotally mounted and pivots between a first position, wherein the weight is in a non-contacting relationship with the optical fiber and a second position, wherein the weight impinges on the optical fiber.
According to a further aspect of the invention, the weight includes a first weight that urges the end portion of the optical fiber into a groove formed in the silicon slab, and a second weight that urges the end portion of the optical fiber onto a flat portion of the silicon slab.
According to another aspect of the invention, a contacting surface of the free end of the weight is parallel to a top portion of the silicon slab when the contacting surface is in contact with the optical fiber.
According to yet another aspect of the invention, the fiber gripping assembly is supplied by a vacuum line, and includes a channel formed therein for establishing fluid communication between the vacuum line and a tip portion of the fiber gripping assembly, wherein the optical fiber is held in the tip portion of the fiber gripping assembly by suction produced in the channel.
According to a further aspect of the invention, the tip portion has a groove formed therein, and the optical fiber is received in the groove. The groove is dimensioned such that a surface of the optical fiber contacts a first side wall of the groove and contacts a second side wall of the groove.
According to an additional aspect of the invention, the first stage is movable on a vertical axis and is rotatable about the vertical axis.
According to an aspect of the invention, the second stage is movable about the Y-axis.
According to still another aspect of the invention, the second stage is connected to a vacuum line, and the silicon slab is exposed to vacuum transmitted via the vacuum line.
According to a further aspect of the invention, the second viewer includes a power and polarization detector, and the second viewer is linked to a motorized servomechanism that actuates at least one of the first stage, and the second stage.
According to yet another aspect of the invention, the first viewer is linked to the servomechanism.
The invention provides a method of manufacturing a fiberoptic array. The method includes disposing a silicon slab on an assembly station, gripping an optical fiber in a first gripping assembly for rotation about a Z-axis therein, gripping the optical fiber in a second gripping assembly for displacement thereof in an X-axis and a Y-axis, visualizing a position of the optical fiber relative the silicon slab, and responsive to the visualization, adjusting the position to a desired position, and then permanently affixing the optical fiber to the silicon slab in the desired position.
According to an additional aspect of the invention, housing is attached to the silicon slab, and the optical fiber is enclosed in the housing.
According to an aspect of the invention, a first groove is formed in the silicon slab. A second groove is formed in the housing, such that the optical fiber is embraced by the first groove and the second groove.
According to another aspect of the invention, the polarization axis of the optical fiber is determined by visualization, and responsive to the determination, the optical fiber is rotated about the Z-axis until its polarization axis attains a desired alignment.
According to a further aspect of the invention, a weight is applied to an intermediate portion of the optical fiber while adjusting the position of the fiber.
The invention provides an apparatus for manufacturing a fiberoptic device, which includes a first stage, a fiber rotator disposed on the first stage, the fiber rotator carrying an optical fiber therein, and rotating the optical fiber about an optical axis thereof. The apparatus further includes a second stage for holding a silicon slab, a fiber gripping assembly disposed between the first stage and the second stage for gripping an intermediate portion of the optical fiber. The fiber gripping assembly is supplied by a first vacuum line, and includes a channel formed therein for establishing fluid communication between the first vacuum line and a tip portion of the fiber gripping assembly. The optical fiber is held in the tip portion of the fiber gripping assembly by suction transmitted via the channel, wherein a groove is formed in the tip portion. The groove is dimensioned such that a surface of the optical fiber contacts both side walls of the groove. A first viewer is directed toward the silicon slab along the Y-axis, and a second viewer is directed toward an end face of the optical fiber in the Z-axis. A third stage is movable on an X-axis and the Z-axis. A first weight and a second weight, are mounted on the third stage, wherein a free end of the first weight and a free end of the second weight impinge on the optical fiber to urge an end portion of the optical fiber against the silicon slab. Responsive to views provided by the first viewer and the second viewer, the first stage, the second stage, the fiber rotator, and the fiber gripping assembly are manipulated to establish the optical fiber in a desired position on the silicon slab.
According to yet another aspect of the invention, the first weight and the second weight are pivotally mounted and independently pivot between a first position of non-contacting relationship with the optical fiber and a second position of impingement on the optical fiber.
According to still another aspect of the invention, the first stage is movable on a vertical axis and is rotatable about the vertical axis.
According to an additional aspect of the invention, the second stage is movable about the Y-axis.
According to an aspect of the invention, the second stage is connected to a second vacuum line, and the silicon slab is exposed to vacuum transmitted via the second vacuum line.